The present invention relates to a connecting method for molded resin products. Also, the present invention relates to a process cartridge detachably mounted to a main assembly of the electrophotographic image forming apparatus, and an assembling method of the process cartridge.
Here, the electrophotographic image forming apparatus forms an image on a recording material through an electrophotographic-image-formation-type process. Examples of electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (a laser beam printer, an LED printer or the like), a facsimile machine and a word processor.
The above-described process cartridge contains as a unit an electrophotographic photosensitive member and a charging means, a developing means or a cleaning means in the form of a cartridge that is detachably mountable to a main assembly of an image forming apparatus. The process cartridge may contain an electrophotographic photosensitive member and at least one of a charging means, a developing means and a cleaning means in the form of a cartridge that is detachably mountably to a main assembly of an image forming apparatus. The process cartridge may contain an electrophotographic photosensitive member and at least developing means in the form of a cartridge that is detachably mountably to a main assembly of an image forming apparatus.
The molded resin product is a molded material of resin material, and may be a frame of the above-described process cartridge, a cap of a toner container and a main body of the container.
A description will be provided as to a conventional toner container which is a molded resin product.
The toner container is used with an electrophotographic image forming apparatus, and accommodates a developer (toner) for developing an electrostatic latent image.
FIG. 1(b) schematically shows a conventional toner container 40. More particularly, it shows a molding method wherein the toner container 42 and the toner container cap 41 are molded using a die slide injection molding method (the primary molding and the secondary molding are carried out using the same metal mold, as disclosed in Japanese Patent Application Publication No. HEI 2-38377, for example. In this molding method, a molten resin material, which is the same material as the toner container 42 and the cap 41, is applied to the abutment portions 142a, 142b, by which the container 42 and the cap 41 are bonded).
The toner container 42 and the cap 41 have the abutment portions 142a, 142b and flanges 143a, 143b, 143c, 143d. In the surface of the flange, there are provided continuous or intermittent recesses or projections 144a, 144b, 144c, 144d extended along the longitudinal direction, which are projected or recessed in a direction not interfering with the removal of the mold. The recess or the projection are engaged in the mold at a predetermined position.
As shown in FIG. 7, a gate 72 which in this molding technique provides an inlet for the bonding material to the abutment portion is provided on a horizontal extension line of the abutment portion 142a, and more particularly, the gap formed between the frames. The molten resin material, as shown in the figure by an arrow 7, flows perpendicularly into the abutment portion 142a through the gate 72 in the horizontal direction.
With this conventional structure, the projected area of the unit after the connection has to be significantly larger than the inside volume thereof (by approximately 3-4 mm) at the connecting portions at each sides.
Additionally, when the cap is manufactured (molded), the direction of the mold removal is limited, with the result that there is less latitude in the design of the product.
The position of the gate is as described in the foregoing. Therefore, the portion of the container not engaged with the metal mold due to the pressure of the resin material upon the resin material injection, is liable to deform inwardly of the container, that is, the direction of the resin material injection through the gate. Furthermore, a high fluid material has to be selected with an increased number of gates.
The resin-material injecting direction is necessarily determined with the result that there is less latitude in the design of the metal molds.
The DSI molding method, as disclosed in Japanese Patent Application Publication No. HEI 2-38377, carries out the primary molding and the secondary molding in the same metal molds. Therefore, the number of the containers which can be bonded is normally two, and if the number is larger, the configurations of the metal molds are very complicated. However, when parts are connected using connecting metal molds other than the molding molds, the container side for one connecting mold has a plurality of cavities (determined by the number of the metal molds and the number of the containers). Therefore, the matching is not good, and there is a liability that a gap results in the molded product and the metal mold and therefore the leakage of the resin material may occur.
The present invention is intended to provide a further development of the above-described conventional technique.
Accordingly, it is a principal object of the present invention to provide a connecting method for molded resin products, a process cartridge and an assembling method of a process cartridge, wherein molded resin parts are assuredly bonded.
It is another object of the present invention to provide a bonding method of molded resin products, a process cartridge, and an assembling method of a process cartridge, wherein molded resin parts having complicated configurations can be connected through a simple process.
It is a further object of the present invention to provide a bonding method of molded resin products, a process cartridge and an assembling method of a process cartridge, wherein molded resin parts can be connected without deformation.
According to an aspect of the present invention, there is provided a bonding method for bonding molded resin products. The improvement resides in the bonding of a first one of the molded resin products and a second one of the molded resin products by injecting resin material through a resin material injection path to a bonding portion therebetween. The resin material injection path is formed in one of or both of the first resin material molded product and the second resin material molded product.
A first one of the molded resin products and a second one of the molded resin products are bonded by injecting resin material through a resin material injection path to a bonding portion therebetween, wherein the resin material injection path is formed in one of or both of the first resin material molded product and the second resin material molded product.
According to another aspect of the present invention, there is provided a bonding method for bonding molded resin products, comprising a first molding step of forming a first resin material molded product by a first metal mold, a second molding step for forming a second resin material molded product by a second metal mold, and a positioning step of placing the first resin material molded product and the second resin material molded product in a third metal mold which is different from the first metal mold and second metal mold and positioning bonding portions of the first resin material molded product and the second resin material molded product. The method also comprises a bonding step of bonding the first resin material molded product and second resin material molded product with each other by injecting a resin material through a resin material injection path to a bonding portion between the first resin material molded product and second resin material molded product. The resin material injection path is provided in one of or both of the first resin material molded product and the second resin material molded product.
According to a further aspect of the present invention, there is provided a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising an electrophotographic photosensitive member, process means actable on the electrophotographic photosensitive member, and an outer wall constituted by bonding a first resin material molded product and a second resin material molded product by injecting resin material through a resin material injection path to a bonding portion between the first resin material molded product and the second resin material molded . The resin material injection path is provided in one of or both of the first resin material molded product and the second resin material molded product.
According to a further aspect of the present invention, there is provided a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising an electrophotographic photosensitive drum, a charge member for electrically charging the electrophotographic photosensitive drum, a developing member for developing an electrostatic latent image formed on the electrophotographic photosensitive drum, a drum frame for supporting the electrophotographic photosensitive drum and the charge member, a developer frame having a developer accommodating portion for accommodating a developer for use by the developing member to develop the electrostatic latent image, and a first end cover bonded to the drum frame and the developer frame by injecting resin material through a resin material injection path to bonding portions between the first end cover and the drum frame and between the first end cover and the developer frame. The first end cover is provided at one side longitudinal ends of the drum frame and the developer frame. The process cartridge also comprises a second end cover bonded to the drum frame and developer frame by injecting resin material through a resin material injection path. The second end cover is provided at the other side longitudinal ends of the drum frame and developer frame.
According to a further aspect of the present invention, there is provided an assembling method of a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising a step of preparing an electrophotographic photosensitive member, a step of preparing process means actable on the electrophotographic photosensitive member, and a step of bonding a first resin material molded product and a second resin material molded product by injecting resin material through a resin material injection path to a bonding portion between the first resin material molded product and second resin material molded product, with the resin material injection path being provided in one of or both of the first resin material molded product and second resin material molded product.
According to a further aspect of the present invention, there is provided an assembling method of a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising a step of preparing a drum frame for supporting an electrophotographic photosensitive drum and a charge member for electrically charging the electrophotographic photosensitive drum. The method also comprises a step of preparing a developer frame having a developer accommodating portion for accommodating a developer for use by a developing member to develop the electrostatic latent image. The method further comprises a first bonding step of bonding a first end cover to the drum frame and to the developer frame by injecting resin material through a resin material injection path to bonding portions between the first end cover and the drum frame and between the first end cover and the drum frame. The first end cover is bonded to one side longitudinal ends of the drum frame and the developer frame. The method also comprises a second bonding step of bonding a second end cover to the drum frame and to the developer frame by injecting resin material a resin material injection path to bonding portions between the second end cover and the drum frame and between the second end cover and the developer frame. The second end cover is bonded to the other side ends of the drum frame, a lower developing cover and a developer frame.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.